Continuous casting molds of this type are described, for example, in German Patent Document DE-A1 4 131 829 and can comprise the cooled broad sidewalls and narrow side walls. The upper shaping parts of these narrow walls and broad walls abut respective upper portion of the slab's opposite side walls until the slab reaches the outlet of the ingot mold where support parts are provided. The support parts are closed by a starting head for start up of the continuous casting operation.
The adjustability of the narrow sidewalls allows the desired width of the thin slab to be set.
This type of mold has the drawback that, especially at high casting speeds, there is a danger of crack development at the edges of the thin slab. Such cracks can lead to a reduction in the quality of rolled products resulting from the rolling of the continuously cast slab.
In German Patent Document DE-A2 1 906 261, which refers to billet molds, some 300 to 500 mm below the level of the melt gaps are provided at the corners of the mold walls and these corner gaps are covered with heat insulating wall plates. The resulting mold is expensive and a sealing at the end by a starting head is exceptionally difficult. Changes in the size of the billets which are to be produced is rendered difficult because of a rigid interconnection of the walls. The heat insulation of the corners is disadvantageous for high speed casting of thin slabs.